In a vehicle such as an electric vehicle, a hybrid vehicle, a fuel-cell electric vehicle and the like that is configured to be capable of generating a vehicle driving force by an electric motor, a power storage device storing electric power for driving the electric motor is mounted. In such a vehicle, electric power is supplied from the power storage device to the electric motor at the time of start-up, acceleration and the like of the vehicle for generating a vehicle driving force while electric power generated by regenerative braking of the electric motor during running on a downhill, during deceleration and the like is supplied to the power storage device.
It is proposed for the above-described vehicle to provide a configuration allowing electrical connection to a power supply external to the vehicle such as a commercial power supply (which will be hereinafter simply referred to as an “external power supply”) so that the power storage device can be charged (which will be hereinafter simply referred to as “external charging”). For example, the so-called plug-in hybrid vehicle is known that has a power storage device chargeable from a power supply of an ordinary household by connecting a power supply outlet provided at the house and a charging inlet provided at the vehicle by means of a charging cable. This allows an increase in fuel consumption efficiency of a hybrid vehicle.
For example, Japanese Patent Laying-Open No. 2011-15567 (PTL 1) discloses an electrically powered vehicle including a power storage device, an inverter driving a rotating electric machine for vehicle running with the electric power of the power storage device, and a charging device for charging the power storage device with the electric power of an external power supply. In this PTL 1, the charging device includes a relay for switching a power feeding path extending from the external power supply to the power storage device so as not to cut off the path between the power storage device and the inverter. The charging device further includes a control device for determining whether the relay is welded or not while controlling the relay to be kept in an opened state during a switching operation of the inverter.